SECTION 092500 - GYPSUM BOARD PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. 1.2 SUMMARY A. Section Includes: 1. Interior gypsum board. 2. Exterior gypsum board for ceilings and soffits. 3. Tile backing panels. B. Related Sections: 1. Division 06 Section "Miscellaneous Rough Carpentry" for wood framing and furring that supports gypsum board. 2. Division 06 Section "Sheathing" for gypsum sheathing. 3. Division 07 Section "Thermal Insulation" for insulation and vapor retarders installed in assemblies that incorporate gypsum board. 4. Division 07 Section "Fire-Resistive Joint Systems" for head-of-wall assemblies that incorporate gypsum board. 5. Division 09 Section "Non-Structural Metal Framing" for non-structural framing and suspension systems that support gypsum board. 6. Division 09 Section "Gypsum Board Shaft Wall Assemblies" for metal shaft-wall framing, gypsum shaft liners, and other components of shaft-wall assemblies. 7. Division 09 Painting Sections for primers applied to gypsum board surfaces. 1.3 SUBMITTALS A. Product Data: For each type of product indicated. B. Samples: For the following products: 1. Trim Accessories: Full-size Sample in 12-inch- long length for each trim accessory indicated. 1.4 QUALITY ASSURANCE A. Fire-Resistance-Rated Assemblies: For fire-resistance-rated assemblies, provide materials and construction identical to those tested in assembly indicated according to ASTM E 119 by an independent testing agency. GYPSUM BOARD 092500-1
B. STC-Rated Assemblies: For STC-rated assemblies, provide materials and construction identical to those tested in assembly indicated according to ASTM E 90 and classified according to ASTM E 413 by an independent testing agency. 1.5 STORAGE AND HANDLING A. Store materials inside under cover and keep them dry and protected against damage from weather, condensation, direct sunlight, construction traffic, and other causes. Stack panels flat to prevent sagging. 1.6 PROJECT CONDITIONS A. Environmental Limitations: Comply with ASTM C 840 requirements or gypsum board manufacturer's written recommendations, whichever are more stringent. B. Do not install interior products until installation areas are enclosed and conditioned. C. Do not install panels that are wet, those that are moisture damaged, and those that are mold damaged. 1. Indications that panels are wet or moisture damaged include, but are not limited to, discoloration, sagging, or irregular shape. 2. Indications that panels are mold damaged include, but are not limited to, fuzzy or splotchy surface contamination and discoloration. PART 2 - PRODUCTS 2.1 PANELS, GENERAL A. Size: Provide in maximum lengths and widths available that will minimize joints in each area and that correspond with support system indicated. 2.2 INTERIOR GYPSUM BOARD A. General: Complying with ASTM C 36/C 36M or ASTM C 1396/C 1396M, as applicable to type of gypsum board indicated and whichever is more stringent. 1. Acceptable Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following: B. Regular Type: a. American Gypsum Co. b. BPB America Inc. c. G-P Gypsum. d. Lafarge North America Inc. e. National Gypsum Company. f. USG Corporation. 1. Thickness: 3/8 inch or 1/2 inch. GYPSUM BOARD 092500-2
C. Type X: 1. Thickness: 5/8 inch. D. Type C: 1. Thickness: As required by fire-resistance-rated assembly indicated on Drawings. E. Flexible Type: Manufactured to bend to fit radii and to be more flexible than standard regular-type gypsum board of same thickness. 1. Thickness: 1/4 inch. F. Ceiling Type: Manufactured to have more sag resistance than regular-type gypsum board. 1. Thickness: 1/2 inch. G. Abuse-Resistant Type: Manufactured to produce greater resistance to surface indentation, throughpenetration (impact resistance), and abrasion than standard, regular-type and Type X gypsum board. 1. Core: As indicated on Drawings. H. Moisture- and Mold-Resistant Type: With moisture- and mold-resistant core and surfaces. 1. Core: 5/8 inch, Type X. 2.3 EXTERIOR GYPSUM BOARD FOR CEILINGS AND SOFFITS A. Exterior Gypsum Soffit Board: ASTM C 931/C 931M or ASTM C 1396/C 1396M, with manufacturer's standard edges. 1. Acceptable Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following: a. American Gypsum Co. b. BPB America Inc. c. G-P Gypsum. d. Lafarge North America Inc. e. National Gypsum Company. f. USG Corporation. 2. Core: As indicated. B. Glass-Mat Gypsum Sheathing Board: Refer to Division 06 Section Sheathing. GYPSUM BOARD 092500-3
2.4 TILE BACKING PANELS A. Water-Resistant Gypsum Backing Board: ASTM C 630/C 630M or ASTM C 1396/C 1396M. 1. Acceptable Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following: a. American Gypsum Co. b. BPB America Inc. c. G-P Gypsum. d. Lafarge North America Inc. e. National Gypsum Company. f. USG Corporation. 2. Core: As indicated on Drawings. B. Glass-Mat, Water-Resistant Backing Board: 1. Complying with ASTM C 1178/C 1178M. a. Product: Subject to compliance with requirements, provide "DensShield Tile Guard" by G- P Gypsum, GlasRoc by CertainTeed or e 2 XP by National Gypsum, or equal. 2. Core: As indicated on Drawings. C. Cementitious Backer Units: ANSI A118.9. 1. Acceptable Products: Subject to compliance with requirements, products that may be incorporated into the Work include, but are not limited to, the following: a. Custom Building Products; Wonderboard. b. FinPan, Inc.; Util-A-Crete Concrete Backer Board. c. USG Corporation; DUROCK Cement Board. 2. Thickness: As indicated on Drawings. 2.5 TRIM ACCESSORIES A. Interior Trim: ASTM C 1047. 1. Material: Galvanized or aluminum-coated steel sheet, rolled zinc, plastic, or paper-faced galvanized steel sheet. 2. Shapes: a. Cornerbead. b. Bullnose bead. c. LC-Bead: J-shaped; exposed long flange receives joint compound. d. L-Bead: L-shaped; exposed long flange receives joint compound. e. U-Bead: J-shaped; exposed short flange does not receive joint compound. f. Expansion (control) joint. g. Curved-Edge Cornerbead: With notched or flexible flanges. B. Exterior Trim: ASTM C 1047. GYPSUM BOARD 092500-4
1. Material: Hot-dip galvanized steel sheet, plastic, or rolled zinc. 2. Shapes: a. Cornerbead. b. LC-Bead: J-shaped; exposed long flange receives joint compound. c. Expansion (Control) Joint: One-piece, rolled zinc with V-shaped slot and removable strip covering slot opening. C. Aluminum Trim: Extruded accessories of profiles and dimensions indicated. 1. Acceptable Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following: a. Fry Reglet Corp. b. Gordon, Inc. c. Pittcon Industries. 2. Aluminum: Alloy and temper with not less than the strength and durability properties of ASTM B 221, Alloy 6063-T5. 3. Finish: Corrosion-resistant primer compatible with joint compound and finish materials specified. 2.6 JOINT TREATMENT MATERIALS A. General: Comply with ASTM C 475/C 475M. B. Joint Tape: 1. Interior Gypsum Wallboard: Paper. 2. Exterior Gypsum Soffit Board: Paper. 3. Glass-Mat Gypsum Sheathing Board: 10-by-10 glass mesh. 4. Tile Backing Panels: As recommended by panel manufacturer. C. Joint Compound for Interior Gypsum Wallboard: For each coat use formulation that is compatible with other compounds applied on previous or for successive coats. 1. Prefilling: At open joints, rounded or beveled panel edges, and damaged surface areas, use setting-type taping compound. 2. Embedding and First Coat: For embedding tape and first coat on joints, fasteners, and trim flanges, use setting-type taping compound. a. Use setting-type compound for installing paper-faced metal trim accessories. 3. Fill Coat: For second coat, use setting-type, sandable topping compound. 4. Finish Coat: For third coat, use setting-type, sandable topping compound. 5. Skim Coat: For final coat of Level 5 finish, use setting-type, sandable topping compound or highbuild interior coating product designed for application by airless sprayer and to be used instead of skim coat to produce Level 5 finish. D. Joint Compound for Exterior Applications: 1. Exterior Gypsum Soffit Board: Use setting-type taping compound and setting-type, sandable topping compound. 2. Glass-Mat Gypsum Sheathing Board: As recommended by sheathing board manufacturer. GYPSUM BOARD 092500-5
E. Joint Compound for Tile Backing Panels: 1. Water-Resistant Gypsum Backing Board: Use setting-type taping compound and setting-type, sandable topping compound. 2. Glass-Mat, Water-Resistant Backing Panel: As recommended by backing panel manufacturer. 3. Cementitious Backer Units: As recommended by backer unit manufacturer. 2.7 AUXILIARY MATERIALS A. General: Provide auxiliary materials that comply with referenced installation standards and manufacturer's written recommendations. B. Laminating Adhesive: Adhesive or joint compound recommended for directly adhering gypsum panels to continuous substrate. 1. Use adhesives that have a VOC content of 50 g/l or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24). C. Steel Drill Screws: ASTM C 1002, unless otherwise indicated. 1. Use screws complying with ASTM C 954 for fastening panels to steel members from 0.033 to 0.112 inch thick. 2. For fastening cementitious backer units, use screws of type and size recommended by panel manufacturer. D. Sound Attenuation Blankets: ASTM C 665, Type I (blankets without membrane facing) produced by combining thermosetting resins with mineral fibers manufactured from glass, slag wool, or rock wool. 1. Fire-Resistance-Rated Assemblies: Comply with mineral-fiber requirements of assembly. E. Acoustical Sealant: As specified in Division 07 Section "Joint Sealants." 1. Provide sealants that have a VOC content of 250 g/l or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24). F. Thermal Insulation: As specified in Division 07 Section "Thermal Insulation." G. Vapor Retarder: As specified in Division 07 Section "Thermal Insulation." PART 3 - EXECUTION 3.1 EXAMINATION A. Examine areas and substrates, with Installer present, and including welded hollow-metal frames and framing, for compliance with requirements and other conditions affecting performance. B. Examine panels before installation. Reject panels that are wet, moisture damaged, and mold damaged. C. Proceed with installation only after unsatisfactory conditions have been corrected. GYPSUM BOARD 092500-6
3.2 APPLYING AND FINISHING PANELS, GENERAL A. Comply with ASTM C 840. B. Install ceiling panels across framing to minimize the number of abutting end joints and to avoid abutting end joints in central area of each ceiling. Stagger abutting end joints of adjacent panels not less than one framing member. C. Install panels with face side out. Butt panels together for a light contact at edges and ends with not more than 1/16 inch of open space between panels. Do not force into place. D. Locate edge and end joints over supports, except in ceiling applications where intermediate supports or gypsum board back-blocking is provided behind end joints. Do not place tapered edges against cut edges or ends. Stagger vertical joints on opposite sides of partitions. Do not make joints other than control joints at corners of framed openings. E. Form control and expansion joints with space between edges of adjoining gypsum panels. F. Cover both faces of support framing with gypsum panels in concealed spaces (above ceilings, etc.), except in chases braced internally. 1. Unless concealed application is indicated or required for sound, fire, air, or smoke ratings, coverage may be accomplished with scraps of not less than 8 sq. ft. in area. 2. Fit gypsum panels around ducts, pipes, and conduits. 3. Where partitions intersect structural members projecting below underside of floor/roof slabs and decks, cut gypsum panels to fit profile formed by structural members; allow 1/4- to 3/8-inch- wide joints to install sealant. G. Isolate perimeter of gypsum board applied to non-load-bearing partitions at structural abutments, except floors. Provide 1/4- to 1/2-inch- wide spaces at these locations, and trim edges with edge trim where edges of panels are exposed. Seal joints between edges and abutting structural surfaces with acoustical sealant. H. Attachment to Steel Framing: Attach panels so leading edge or end of each panel is attached to open (unsupported) edges of stud flanges first. I. STC-Rated Assemblies: Seal construction at perimeters, behind control joints, and at openings and penetrations with a continuous bead of acoustical sealant. Install acoustical sealant at both faces of partitions at perimeters and through penetrations. Comply with ASTM C 919 and with manufacturer's written recommendations for locating edge trim and closing off sound-flanking paths around or through assemblies, including sealing partitions above acoustical ceilings. J. Install sound attenuation blankets before installing gypsum panels, unless blankets are readily installed after panels have been installed on one side. 3.3 APPLYING INTERIOR GYPSUM BOARD A. Install interior gypsum board in the following locations: 1. Regular Type: As indicated on Drawings. 2. Type X: As indicated on Drawings. 3. Type C: As indicated on Drawings. 4. Flexible Type: Apply in double layer at curved assemblies. GYPSUM BOARD 092500-7
5. Abuse-Resistant Type: As indicated on Drawings. 6. High-Impact Type: As indicated on Drawings. 7. Moisture- and Mold-Resistant Type: As indicated on Drawings. B. Single-Layer Application: 1. On ceilings, apply gypsum panels before wall/partition board application to greatest extent possible and at right angles to framing, unless otherwise indicated. 2. On partitions/walls, apply gypsum panels vertically (parallel to framing), unless otherwise indicated or required by fire-resistance-rated assembly, and minimize end joints. a. Stagger abutting end joints not less than one framing member in alternate courses of panels. b. At stairwells and other high walls, install panels horizontally, unless otherwise indicated or required by fire-resistance-rated assembly. 3. On Z-furring members, apply gypsum panels vertically (parallel to framing) with no end joints. Locate edge joints over furring members. 4. Fastening Methods: Apply gypsum panels to supports with steel drill screws. C. Multilayer Application: 1. On ceilings, apply gypsum board indicated for base layers before applying base layers on walls/partitions; apply face layers in same sequence. Apply base layers at right angles to framing members and offset face-layer joints 1 framing member, 16 inches minimum, from parallel baselayer joints, unless otherwise indicated or required by fire-resistance-rated assembly. 2. On partitions/walls, apply gypsum board indicated for base layers and face layers vertically (parallel to framing) with joints of base layers located over stud or furring member and face-layer joints offset at least one stud or furring member with base-layer joints, unless otherwise indicated or required by fire-resistance-rated assembly. Stagger joints on opposite sides of partitions. 3. On Z-furring members, apply base layer vertically (parallel to framing) and face layer either vertically (parallel to framing) or horizontally (perpendicular to framing) with vertical joints offset at least one furring member. Locate edge joints of base layer over furring members. 4. Fastening Methods: Fasten base layers and face layers separately to supports with screws. D. Laminating to Substrate: Where gypsum panels are indicated as directly adhered to a substrate (other than studs, joists, furring members, or base layer of gypsum board), comply with gypsum board manufacturer's written recommendations and temporarily brace or fasten gypsum panels until fastening adhesive has set. E. Curved Surfaces: 1. Install panels horizontally (perpendicular to supports) and unbroken, to extent possible, across curved surface plus 12-inch- long straight sections at ends of curves and tangent to them. 2. For double-layer construction, fasten base layer to studs with screws 16 inches o.c. Center gypsum board face layer over joints in base layer, and fasten to studs with screws spaced 12 inches o.c. 3.4 APPLYING EXTERIOR GYPSUM PANELS FOR CEILINGS AND SOFFITS A. Apply panels perpendicular to supports, with end joints staggered and located over supports. 1. Install with 1/4-inch open space where panels abut other construction or structural penetrations. GYPSUM BOARD 092500-8
2. Fasten with corrosion-resistant screws. 3.5 APPLYING TILE BACKING PANELS A. Water-Resistant Gypsum Backing Board: Install at showers, tubs, and where indicated. Install with 1/4- inch gap where panels abut other construction or penetrations. B. Cementitious Backer Units: ANSI A108.11. C. Areas Not Subject to Wetting: Install regular-type gypsum wallboard panels to produce a flat surface except at showers, tubs, and other locations indicated to receive water-resistant panels. D. Where tile backing panels abut other types of panels in same plane, shim surfaces to produce a uniform plane across panel surfaces. 3.6 INSTALLING TRIM ACCESSORIES A. General: For trim with back flanges intended for fasteners, attach to framing with same fasteners used for panels. Otherwise, attach trim according to manufacturer's written instructions. B. Control Joints: Install control joints at locations indicated on Drawings and according to ASTM C 840 and in specific locations approved by Architect for visual effect. C. Interior Trim: Install in the following locations: 1. Cornerbead: Use at outside corners, unless otherwise indicated. 2. Bullnose Bead: Use where indicated. 3. LC-Bead: Use at exposed panel edges. 4. L-Bead: Use where indicated. 5. Curved-Edge Cornerbead: Use at curved openings. D. Exterior Trim: Install in the following locations: 1. Cornerbead: Use at outside corners. 2. LC-Bead: Use at exposed panel edges. E. Aluminum Trim: Install in locations indicated on Drawings. 3.7 FINISHING GYPSUM BOARD A. General: Treat gypsum board joints, interior angles, edge trim, control joints, penetrations, fastener heads, surface defects, and elsewhere as required to prepare gypsum board surfaces for decoration. Promptly remove residual joint compound from adjacent surfaces. B. Prefill open joints, rounded or beveled edges, and damaged surface areas. C. Apply joint tape over gypsum board joints, except those with trim having flanges not intended for tape. D. Gypsum Board Finish Levels: Finish panels to levels indicated below and according to ASTM C 840: 1. Level 1: Ceiling plenum areas, concealed areas, and where indicated. GYPSUM BOARD 092500-9
2. Level 2: Panels that are substrate for tile. 3. Level 4: At panel surfaces that will be exposed to view, unless otherwise indicated. a. Primer and its application to surfaces are specified in other Division 09 Sections. 4. Level 5: Where indicated on Drawings surfaces receiving gloss and semigloss enamels and other surfaces subject to severe lighting. a. Primer and its application to surfaces are specified in other Division 09 Sections. E. Cementitious Backer Units: Finish according to manufacturer's written instructions. 3.8 PROTECTION A. Protect installed products from damage from weather, condensation, direct sunlight, construction, and other causes during remainder of the construction period. B. Remove and replace panels that are wet, moisture damaged, and mold damaged. 1. Indications that panels are wet or moisture damaged include, but are not limited to, discoloration, sagging, or irregular shape. 2. Indications that panels are mold damaged include, but are not limited to, fuzzy or splotchy surface contamination and discoloration. END OF SECTION 092500 GYPSUM BOARD 092500-10